DIY TDS CALIBRATION SOLUTIONS

Ever wanted to calibrate your TDS pen, or check its calibration? I wanted to see how accurate my cheap ebay pen for $12 was but didn't have any calibration solutions. 
After a bit of searching this is what I came up with for a simple DIY solution:

To get a 2000ppm solution would need to put 2g of table salt (NaCl) into 1L of RO water.. or just put 1g of salt into .5L of RO water. Dilute accordingly for a range of solutions, just be careful to measure accurately and STIR IT UP WELL.

I based this DIY TDS solution recipe on How to Make Calibration Solutions.
This link can also teach you how to make a TDS meter if you are feeling handy.